I want to have multiple subdomains running of a single install of Wordpress. e.g. blue.mysite.com yellow.mysite.com green.mysite.com I basically want to have my categories as subdomains. MU has been discontinued, and is "continuing development as part of the main WordPress". When I looked at the multi user/subdomain docs for the regular version of WP, I see this - "It is not recommended to try this on shared hosting". ... And I'm running on shared hosting. It also looks more complicated that I thought it would be. WP Subdomain plugin looks good, but is only compatible up to version 2.9.2 - http://wordpress.org/extend/plugins/wordpress-subdomains/ So what now? Am I missing an easy solution?
No you are not missing anything. It is possible to do it, and yes shared hosting is not the best option for setting it up. You can however set up the multi site function using folders. yoursite.com/blue, yoursite.com/green. Shared hosting is not good for any multi site set up, but you may have an easier time with the folder option.
Folders are no good. I've got a domain that would work nicely with subdomains (e.g car.hire.com, boat.hire.com, van.hire.com), and would like to run it off a single instance of Wordpress. All I want is for my categories to be subdomains. Simplest solution would be to run WP 2.9.2 and the WP Subdomains plugin?
I understand what you want, but you are not addressing what you have. If you want to run MU with subdomains then upgrade your hosting. I don't recommend running an older version of WP just to try and shortcut the real issue. I'm not saying that it won't work on subdomains. It's just not recommended. I don't know for sure that it won't work, I've never installed it on shared hosting. First step is to check with your host and see if they even allow you to set the wildcard for subdomains. If they don't then it doesn't matter what version of WP you use, it will still never work.
What about WPMU + wildcard DNS (hostgator) If you can't have wildecard DNS you can try WPMU + Domain mapping
Thanks, one last question, if the single wp is already installed, set up with plugins, can i convert it to MU later? Or MU installation must be done on really fresh wordpress installation?
No, you can set it up later. Whether or not you can set it up as subdomains or folders will depend on what else you have installed on the root. If there is nothing else on the root, you should be able to choose either.